>So the core of my worry is basically, 'Surely you can't just boot off the dist
>ribution media, get a barebones TTY window and then Amanda will restore
>everything with an under-the-covers tar -xvf rmt0 /'????  

It depends on the OS, but you're right, there is usually some other work
you will have to do before turning Amanda loose on the bulk of the data.

>There are two problems, right away
>1) I guess you have to reconstruct the partitions first (in Linux too?)

If you're starting from a brand new disk, then yes.

>2) What do you do about boot records, hidden system files ...

You figure out what you need to do ahead of time (as I said, installboot
for Solaris, and Bernhard gave the basics for Linux) and write it down
on paper in your procedures book.  :-)

Some OS's (I think Linux falls in this category) have packages that
let you create a boot-able medium that can do a lot of this for you,
ala mksysb.  But that's a Linux question, not an Amanda one (although
there is probably plenty of expertise on this list).

FYI, there has been some discussion in the past about adding special
files to the Amanda tapes to help with disaster recovery.  For instance,
it could be a tar of various config files to make putting things back
together easier.  Or it could be a script that actually did the work
(writing the script would be an exercise left to you :-).

>... and sparsely-written
> data (you *don't* restore Oracle from a  tar tape, fr'instance)...

Now you've gone "below" Amanda.  Amanda is a manager of other backup
programs.  It does not actually do backups itself (it doesn't read the
disk, etc).

However, all dump style programs (backup, ufsdump, dump, etc) handle
sparse files.  What comes back will be what was there to start with.

GNU tar can also do sparse files, and Amanda runs it with the flags
needed to do so.

Databases (e.g. Oracle), though, are another matter.  Those are not
just sparse files.  They are also "live" and you can't just back them up
while the engine is running.  There are numerous ways around this (check
the mailing list archives).  We run Oracle here and do it by having a
large "backup" area that we tell Oracle to write its own backups into,
then we use Amanda to dump that.  See:

  ftp://gandalf.cc.purdue.edu/pub/amanda/dbbackup.*

It's a little out of date, but should still work.  And yes, I've even
had to restore from them.

>... and these will be different with each OS
>and then there are possible other concerns..

Yup.  In general, you need to know what you're doing.  That's why us
backup folks rake in the huge bucks :-).

>3) You have booted (off the installation media, I guess) and are running syste
>m code...what happens when you overwrite code you're running.  ...

Ummm, if you booted off installation media, such as a CD-ROM, you *can't*
overwrite the code being run :-).  It's called "Read-Only" for a reason.

Taking Solaris as an example, I would boot off the CD and at that point
(well, after answering a lot of annoying questions), I'd have a normal
TTY window, but it's all associated with the CD.  Next I'd re-partition
the disk drive (if needed), newfs the partitions, and finally mount and
restore into them.  FYI, I've done this lots of times.  I don't even
bother waking up any more :-).

Note that you don't need Amanda laying around to do this.  Amanda tape
images can be processed with normal Unix tools (mt, dd and whatever
restore program matches the dump format).

The one thing you might want to be careful about is compression.  Just to
be safe, I would probably *never* software compress my OS file systems
on the off chance I didn't have the uncompress program during such a
disaster recovery.

>S.

John R. Jackson, Technical Software Specialist, [EMAIL PROTECTED]

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